• Title/Summary/Keyword: copy number

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Role of GSTM1 Copy Number Variant in the Prognosis of Thai Colorectal Cancer Patients Treated with 5-FU-based Chemotherapy

  • Pongtheerat, Tanett;Saelee, Pensri
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.10
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    • pp.4719-4722
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    • 2016
  • Background: Glutathione S-transferase M1 (GSTM1) is involved in the detoxification of carcinogenic agents. DNA copy number variants of GSTM1 may be associated with cancer progression and may result in reduced survival time of various cancers. Determination of DNA copy number variants was here used to assess the association between GSTM1 copy number variant and pathological status and survival time of colorectal-cancer patients treated with 5-fluorouracil-based chemotherapy. Methods: One hundred thirteen Thai colorectal-cancer patients were investigated for GSTM1 copy number variant by real-time PCR. Relationships between gene copy number variants and clinico-pathological parameters were determined. Result: Associations were evident between GSTM1 copy number and stage of tumor (P = 0.026) and metastasis at diagnosis (P = 0.049), with odds ratio values of 0.2 and 0.3 respectively. Conclusions: GSTM1 copy number variant was here not related with reduced overall survival for the colorectal-cancer patients receiving 5-FU-based chemotherapy.

Mitochondrial Genome Microsatellite Instability and Copy Number Alteration in Lung Carcinomas

  • Dai, Ji-Gang;Zhang, Zai-Yong;Liu, Quan-Xing;Min, Jia-Xin
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2393-2399
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    • 2013
  • Objective: Mitochondrial DNA (mtDNA) is considered a hotspot of mutations in various tumors. However, the relationship between microsatellite instability (MSI) and mtDNA copy number alterations in lung cancer has yet to be fully clarifieds. In the current study, we investigated the copy number and MSI of mitochondrial genome in lung carcinomas, as well as their significance for cancer development. Methods: The copy number and MSI of mtDNA in 37 matched lung carcinoma/adjacent histological normal lung tissue samples were examined by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) assays for sequence variation, followed by sequence analysis and fluorogenic 5'-nuclease real-time PCR. Student's t test and linear regression analyses were employed to analyze the association between mtDNA copy number alterations and mitochondrial MSI (mtMSI). Results: The mean copy number of mtDNA in lung carcinoma tissue samples was significantly lower than that of the adjacent histologically normal lung tissue samples (p<0.001). mtMSI was detected in 32.4% (12/37) of lung carcinoma samples. The average copy number of mtDNA in lung carcinoma samples containing mtMSI was significantly lower than that in the other lung carcinoma samples (P<0.05). Conclusions: Results suggest that mtMSI may be an early and important event in the progression of lung carcinogenesis, particularly in association with variation in mtDNA copy number.

Simultaneous Overexpression of Integrated Genes by Copy Number Amplification of a Mini-Yeast Artificial Chromosome

  • Jung, Heo-Myung;Kim, Yeon-Hee
    • Journal of Microbiology and Biotechnology
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    • v.28 no.5
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    • pp.821-825
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    • 2018
  • A copy number amplification system for yeast artificial chromosomes (YACs) was combined with simultaneous overexpression of genes integrated into a YAC. The chromosome VII (1,105 kb) was successfully split to 887 kb, 44 kb containing the element for copy number amplification, and a 184-kb split-YAC. The 44-kb split-mini YAC was amplified a maximum of 9-fold, and the activity of the reporter enzymes integrated into the split-mini YAC increased about 5-7-fold. These results demonstrate that the mini-YAC containing a targeted chromosome region can be readily amplified, and the specific genes in the mini-YAC could be overexpressed by increasing the copy number.

Relationship Between Mitochondrial DNA Copy Number, Metabolic Abnormalities and Hepatic Steatosis (지방간 및 대사 인자들과 말초혈액 백혈구의 사립체 DNA copy 수와의 연관성)

  • Kwon, Kil-Young;Jun, Dae-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.6
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    • pp.2093-2098
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    • 2010
  • Insulin resistance plays a central role in fatty liver, a part of the metabolic syndrome. This study examined the relationship between fatty liver, metabolic abnormalities and mitochondrial DNA [mtDNA] copy number in peripheral blood that is correlated with diabetes or metabolic markers. Fatty liver was assessed by questionnaire on alcohol consumption and abdominal ultrasonography. MtDNA copy number in peripheral leukocytes was measured by a real-time quantitative polymerase chain reaction [PCR]. Among 445 subjects, 148 subjects had hepatic steatosis and 297 were controls. mtDNA copy number was significantly lower in fatty liver group in comparison with that of normal finding group. This result is similar in both groups, alcoholic or non-alcoholic fatty liver group. MtDNA copy number was inversely correlated with alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma-glutamyltransferase [$\gamma$-GTP], body mass index [BMI], waist circumference, diastolic blood pressure, and free fatty acid. MtDNA copy number in peripheral leukocytes was associated with fatty liver and insulin resistance related factors.

A Penalized Spline Based Method for Detecting the DNA Copy Number Alteration in an Array-CGH Experiment

  • Kim, Byung-Soo;Kim, Sang-Cheol
    • The Korean Journal of Applied Statistics
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    • v.22 no.1
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    • pp.115-127
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    • 2009
  • The purpose of statistical analyses of array-CGH experiment data is to divide the whole genome into regions of equal copy number, to quantify the copy number in each region and finally to evaluate its significance of being different from two. Several statistical procedures have been proposed which include the circular binary segmentation, and a Gaussian based local regression for detecting break points (GLAD) by estimating a piecewise constant function. We propose in this note a penalized spline regression and its simultaneous confidence band(SCB) approach to evaluate the statistical significance of regions of genetic gain/loss. The region of which the simultaneous confidence band stays above 0 or below 0 can be considered as a region of genetic gain or loss. We compare the performance of the SCB procedure with GLAD and hidden Markov model approaches through a simulation study in which the data were generated from AR(1) and AR(2) models to reflect spatial dependence of the array-CGH data in addition to the independence model. We found that the SCB method is more sensitive in detecting the low level copy number alterations.

Correlation of virus replication and spleen index in rock bream iridovirus infected rock bream Oplegnathus fasciatus

  • Jung, Myung-Hwa;Jung, Sung-Ju
    • Journal of fish pathology
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    • v.32 no.1
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    • pp.1-8
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    • 2019
  • Rock bream iridovirus (RBIV) is a member of the Megalocytivirus genus that causes severe mortality to rock bream (Oplegnathus fasciatus) with characteristic clinical signs of spleen enlargement. In this study, we assessed spleen size and RBIV copy number patterns in RBIV-infected rock bream to determine lethal and safe levels of virus copy number/spleen index that may define disease progress. We found that rock bream infected with RBIV ($1.1{\times}10^7virus\;copy\;number/100{\mu}l$) and held at 29, 26, 23 or $20^{\circ}C$ exhibited significantly higher levels of spleen size compared to $17^{\circ}C$. In dead condition (100% mortality at $20{\sim}29^{\circ}C$), the spleen index ($spleen\;weight/fish\;weight{\times}100$) and virus copy number were 3.00~5.38 and $10^6{\sim}10^8/{\mu}l$, respectively. Conversely, in survived condition (0% mortality at $17^{\circ}C$), spleen index and virus copy number was as low as not-infected control ($0.34{\sim}1.22/10^0{\sim}10^1/{\mu}l$, respectively). These findings suggest that spleen index can be an indicator of disease severity of RBIV disease.

CGHscape: A Software Framework for the Detection and Visualization of Copy Number Alterations

  • Jeong, Yong-Bok;Kim, Tae-Min;Chung, Yeun-Jun
    • Genomics & Informatics
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    • v.6 no.3
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    • pp.126-129
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    • 2008
  • The robust identification and comprehensive profiling of copy number alterations (CNAs) is highly challenging. The amount of data obtained from high-throughput technologies such as array-based comparative genomic hybridization is often too large and it is required to develop a comprehensive and versatile tool for the detection and visualization of CNAs in a genome-wide scale. With this respective, we introduce a software framework, CGHscape that was originally developed to explore the CNAs for the study of copy number variation (CNV) or tumor biology. As a standalone program, CGHscape can be easily installed and run in Microsoft Windows platform. With a user-friendly interface, CGHscape provides a method for data smoothing to cope with the intrinsic noise of array data and CNA detection based on SW-ARRAY algorithm. The analysis results can be demonstrated as log2 plots for individual chromosomes or genomic distribution of identified CNAs. With extended applicability, CGHscape can be used for the initial screening and visualization of CNAs facilitating the cataloguing and characterizing chromosomal alterations of a cohort of samples.

RAN-aCGH: R GUI Tools for Analysis and Visualization of an Array-CGH Experiment

  • Kim, Sang-Cheol;Kim, Byung-Soo
    • Genomics & Informatics
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    • v.5 no.3
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    • pp.137-139
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    • 2007
  • RAN-aCGH is an R GUI tool for the analysis and visualization of array comparative genomic hybridization (array-CGH) experiments. The tool consists of data-loading, preprocessing for missing data, several methods for statistical identification of DNA copy number aberration, and visualization of the copy number change. RAN-aCGH requires a single input format, provides various visualizations, and allows the addition of a new statistical method, all in a user-friendly graphic user interface (GUI).

Web-Based Database and Viewer of East Asian Copy Number Variations

  • Kim, Ji-Hong;Hu, Hae-Jin;Chung, Yeun-Jun
    • Genomics & Informatics
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    • v.10 no.1
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    • pp.65-67
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    • 2012
  • We have discovered copy number variations (CNVs) in 3,578 Korean individuals with the Affymetrix Genome-Wide SNP array 5.0, and 4,003 copy number variation regions (CNVRs) were defined in a previous study. To explore the details of the variants easily in related studies, we built a database, cataloging the CNVs and related information. This system helps researchers browsing these variants with gene and structure variant annotations. Users can easily find specific regions with search options and verify them from system-integrated genome browsers with annotations.

Development of Simultaneous YAC Manipulation-Amplification (SYMA) system by Chromosome Splitting Technique Harboring Copy Number Amplification System (복제수 증폭시스템과 염색체 분단기술을 이용한 Simultaneous YAC Manipulation-Amplification (SYMA) 시스템의 개발)

  • Kim, Yeon-Hee;Nam, Soo-Wan
    • Journal of Life Science
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    • v.20 no.5
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    • pp.789-793
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    • 2010
  • Artificial chromosome manipulation and amplification of single-copy yeast artificial chromosome (YAC) are usually required in order to use YACs for applications such as physical mapping and functional analysis in eukaryotes. We designed and implemented a Simultaneous YAC Manipulation-Amplification (SYMA) system that combines the copy number amplification system of YAC with a convenient YAC manipulation system. To achieve the desired split and to amplify a YAC clone-harboring plant chromosome, a pBGTK plasmid containing a conditional centromere and thymidine kinase (TK) gene was constructed as a template to amplify the splitting fragment via PCR. By splitting, new 490-kb and 100-kb split YACs containing the elements for copy number amplification were simultaneously generated from a 590-kb YAC clone. The 100-kb split YAC was then successfully amplified 14.4-fold by adding 3 mg/ml sulfanilamide and $50\;{\mu}g/ml$ methotrexate (S3/M50) as inducing substances.